Numerous conditions can cause pain in the lower left part of the stomach or abdomen. According to the Merck Manuals website, certain abdominal conditions can cause pain to manifest on one or both sides of the lower abdomen. In most cases, the side of the abdomen in which problems occur is the same side in which pain is felt. However, some cases of one-sided or unilateral abdominal pain may be caused by structures on the opposite side of the abdomen or structures outside the abdomen.
Endometriosis
Endometriosis is a condition of the female reproductive tract that can cause pain in the lower left part of the abdomen. According to MayoClinic.com, endometriosis occurs when endometrial tissue--the tissue that lines the uterus--grows outside the uterus. The ovaries, bowel or the tissue lining the pelvis are common locations for endometriosis. MayoClinic.com notes that it is rare for endometrial tissue to spread beyond the pelvic region. The endometrial tissue growing outside the uterus acts as it would inside the uterus, such that it thickens, breaks down and bleeds during a woman's menstrual cycle. Common signs and symptoms associated with endometriosis include effected-side lower abdominal pain, lower back pain, dysmenorrhea or painful periods, pain with sex, infertility and excessive bleeding. Never giving birth, a family history of endometriosis and a history of pelvic infection are all risk factors associated with this condition.
Mittelschmerz
Mittelschmerz--a condition of the female reproductive tract--can cause pain or discomfort in the lower left side of the stomach or abdomen. The MedlinePlus website states that mittelschmerz, or ovulation-related pain, is one-sided, lower abdominal pain that develops around the time when an egg is released from the ovary. According to the MedlinePlus website, approximately 20 percent of women experience mittelschmerz. Mittelschmerz-related pain may manifest before, during or after ovulation. Common signs and symptoms associated with mittelschmerz include one-sided lower abdominal pain that is sharp or cramping, pain that lasts anywhere from a few minutes to a few hours and lower abdominal pain that may switch sides from month to month. The MedlinePlus website states that mittelschmerz-related pain is not harmful and does not indicate a serious underlying disease.
Testicular Torsion
Testicular torsion is a male reproductive tract problem that can cause pain in the lower left abdominal quadrant. According to MayoClinic.com, testicular torsion develops when a testicle rotates on the spermatic cord. The spermatic cord provides blood, oxygen and nutrients to the testicle. Without adequate blood flow to the testicle, a person will experience severe pain and swelling in the affected area. Although it can occur in males of all ages, testicular torsion most commonly affects males between the ages of 10 and 25. Common signs and symptoms associated with testicular torsion include one-sided lower abdominal pain, severe pain in the affected testicle, swelling of the scrotum or the sac that contains the testicles and nausea and vomiting. MayoClinic.com states that testicular torsion usually requires emergency surgery to save the involved testicle.
